Is it possible to convert LVM filesystem back to normal?

My filesystem setup is an LVM setup. I'm wanting to try installing ElementaryOS Luna Beta 1 on its own partition, but unfortunately it doesn't support LVM yet.

Is there any easy way to do this?

If you're willing to wipe everything in the LVM, then yes: Just delete the LVM partition and let the new distribution's installer create whatever it needs, or do so manually before or during the installation.

If you want to save some or all of what's in your LVM, then it gets more complex. One option is to shrink your LVM to make room for the new distribution. This will require either heavy-duty command-line tools like various LVM command and fdisk or gdisk; or use of a GUI LVM front-end like system-config-lvm. Another option is to back up your data, delete the LVM, and restore everything to a non-LVM setup. Another is to install a new hard disk and use that for your new distribution, leaving the current LVM setup intact. Yet another option is to install LVM support into the new distribution. This can probably be done just by adding the right packages to the installer, but I can't be sure of that.

No, you cannot convert LVM logical volumes to partitions.

However, you copy the logical volumes to another back-up disk, delete the LVM physical volumes on the original disk, create new partitions, and restore the data from the back-up.

Alternatively, if you have enough free space on your hard disk, you can shrink the logical volumes, shrink the LVM physical volumes, create new partitions, copy the data from the logical volumes to the partitions, delete the LVM physical volumes, and then grow the partitions.